mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Purple, violet, or lavender
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Formed in hydrothermal veins and cavities (geodes) of igneous rocks when silica-rich water cools. The purple color is caused by irradiation and iron impurities. Often formed during the Jurassic or Cretaceous periods in volcanic basalt.
Uses & applications
Widely used in jewelry (facets and cabochons), ornamental carvings, and highly popular as a metaphysical healing stone or collectible mineral specimen.
Geological facts
The name comes from the Greek word 'amethystos', meaning 'not intoxicated', as it was once believed to prevent drunkenness. It is the birthstone for February.
Field identification & locations
Identify by its purple hexagonal crystals and inability to be scratched by a steel knife. Found commonly in Brazil, Uruguay, Zambia, and South Korea. Collectors should look for deep 'Siberian' purple hues.
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